1. Field of the Invention
The present invention relates to a portable drilling rig for drilling water wells or installing geothermal pipe systems in the ground. More specifically, the present invention is a portable drilling rig that is removably mounted on a truck bed. The rig pivots to a horizontal position on the truck bed for transport and pivots to a vertical position for drilling, or alternately, pivots to a slanted position for drilling at an angle into the ground.
2. Description of the Related Art
Currently the drilling rigs that are used to drill water wells or to install underground piping for use in geothermal heating and cooling installations are large and can not be easily driven into a small area, such as a back yard of an urban residence.
Also, current drilling rigs are not constructed to allow the drive shaft that rotates the pipe drill string and drill bit to pivot so that additional pipe segments can be easily added to the pipe drill string, or alternately, removed from the pipe drill string.
Further, most current drill rigs are not simple enough for a single person to operate.
Finally, other drill rigs are permanently mounted to the vehicle on which they are transported, making the vehicle unsuitable for any other purpose.
The present invention addresses each of these problems by providing a drilling rig that is small and is removably mounted to the bed of a truck. The drilling rig of the present invention is designed with a pivoting swivel that allows a single operator to easily operate the rig to drill a well.
The present invention relates to a portable drilling rig for drilling water wells or installing geothermal pipe systems in the ground. More specifically, the present invention is a portable drilling rig that is removably mounted on a truck bed via a supporting frame that holds the rig on the truck bed. The rig is provided with a pivotal mast that can be pivoted downward to a horizontal position for transport and can be pivoted upward to a vertical position to drill a vertical bore into the ground, or alternately, pivoted upward to a slanted, off-vertical position for drilling an angled bore into the ground.
The mast is pivotally secured to an upwardly extending, supporting pivot leg provided secured to the frame at the rear end of the rig. The mast is raised and lowered by a first hydraulic cylinder that causes the mast to pivot at the supporting pivot leg. When the mast is pivoted downward to its horizontal position, the upper end of the mast is supported by an upwardly extending, front support leg secured to the frame at the front of the frame.
Both the support pivot leg and the front support leg are secured in their upright positions by braces that extend downward and secure to the bottom members of the frame at angles, thus forming triangular bracing with the bottom members of the frame for the legs. Also the bottom members of the frame attach to a double I-beam of the frame located at the rear end to form triangular configurations with the double I-beam. The triangular configurations of the bottom members and the braces of the frame make it strong. A base plate is secured to the double I-beam of the frame at the rear end so that the base plate extends horizontally away from the frame. The base plate has a rectangular bit breaker opening therethrough and a removable plate that attaches over the base plate via bolts. The removable plate has a circular shoe opening extending through it. The function of the base plate and the removable plate will be discussed more fully hereafter.
Also, jacks attach to the lower side of the double I-beam. The jacks can be lowered to the ground to help support the frame above the ground either when the rig is being used for drilling or when the rig is removed from the truck bed. The jacks can be retracted upward toward the frame when the rig is being transported so that they do not drag on the ground.
A swivel is movably attached to the back side of the mast via a pair of mast chains so that the swivel can be moved upward on the mast and lowered downward on the mast when the mast is raised from its horizontal position. One of the two ends of each of the mast chains secures to a top of a non-pivoting portion of the swivel and the other end of each of the mast chains secures to a bottom of the non-pivoting portion of the swivel. Each of the mast chains extends over a mast chain sprocket at the upper end of the mast and each of the mast chains extends around a mast drive sprocket at the lower end of the mast. The mast chain sprockets provided at the upper end of the mast secure to the mast via a common shaft, and the mast drive sprockets at the lower end of the mast secure to the mast via a common shaft. A pair of mast chain drive motors provided on the lower end of the mast rotate the mast drive sprockets via a pair of mast motor drive chains, thus raising and lowering the swivel.
A boom line arm is also pivotally secured to the mast on the upper end of the mast. The boom line arm pivots to a horizontal position when the mast is in its horizontal position, and can be pivoted to a perpendicular position so that the boom line extends outward from the rear end of the rig when the mast is raised from its horizontal position. The boom line arm is provided with a pulley around which a boom cable runs. The boom arm cable removably attaches on one end to a hydraulic winch provided attached to the frame and attaches on an opposite end to the swivel. The winch is activated to pivot the swivel by raising the swivel to a position that is non-parallel with the mast, and alternately, to lower the swivel back to its original position so that it is parallel with the mast. It is necessary to pivot the swivel upward out of alignment with the mast in order to add pipe segments to the bottom end of the swivel when making up a pipe drill string of pipe during drilling operations and also to remove pipe segments from the bottom end of the swivel when pulling and dismantling a pipe drill string.
The swivel is provided with dual swivel drive sprockets at its top end. The dual swivel drive sprockets are secured to a drive shaft via a key that fits into a keyway in the drive shaft. The drive shaft extends from the top end of the swivel, through the swivel, and to the bottom end of the swivel. The dual swivel drive sprockets are driven by two swivel drive motors via a pair of swivel drive chains. Each of the swivel drive chains engages its associated swivel drive sprocket and a drive sprocket provided on its associated swivel drive motor to cause the drive shaft to rotate within the swivel when the rig is being used to drill.
The swivel is provided with bearings adjacent to the dual swivel drive sprockets and the drive shaft rotates within the bearings. The bearings attach to a supporting collar that secures to a pivoting member. The main body of the swivel also attaches via a support arm to the pivoting member to hold the swivel stationary relative to the pivoting member. The pivoting member pivotally attaches via a pivot rod to the non-pivoting portion of the swivel. The pivoting member and the attached swivel, as a unit, pivot at the pivot rod to move the swivel out of parallel alignment with the mast, and alternately, back into parallel alignment with the mast, as previously described. The bearings are retained on the drive shaft by a shoulder provided on the drive shaft at one end of the collar and by a threaded nut on the other end of the collar. The threaded nut engages threads provided on the drive shaft on a portion of the drive shaft located adjacent to the dual swivel drive sprockets.
The drive shaft extends through a main body of the swivel that is located adjacent to the supporting collar and bearings. The main body is comprised of a hollow central cylinder to which an end flange attaches at either end of the central cylinder via lock bolts. The end flanges fit tightly within the central cylinder and an o-ring provided in a o-ring groove in each of the end flanges prevents drilling fluid from exiting the hollow central cylinder by preventing fluid from travelling between the end flange and the central cylinder.
Each end flange has a drive shaft opening in it within which the drive shaft extends. Several gland packing rings are provided internally in the main body adjacent to each of the end flanges. A brass ring is provided adjacent to each set of gland packing rings. Each brass ring secures to the drive shaft via screws so that the gland packing rings are sandwiched between their end flange and their associated brass ring. The distance between a brass ring and its associated end flange can be decreased by tightening the lock bolts in order to compress the gland packing rings so that they tighten around the drive shaft. The gland packing rings prevent drilling fluid from exiting the main body via the drive shaft openings in the end flanges.
The central cylinder is provided with an inlet opening for admitting drilling fluid into the hollow main body of the swivel. The drive shaft is provided with several fluid openings that communicate through the drive shaft. The fluid openings are provided in a portion of the drive shaft that is located within the hollow main body of the swivel. Each of these fluid openings extends through the drive shaft into a hollow segment of the drive shaft. The hollow segment of the drive shaft is continuous with the lower end of the drive shaft so that the drive shaft is hollow as it terminates at the bottom end of the swivel. The lower end of the drive shaft is provided with male threads for removable engagement with mating female threads provided on segments of drill pipe. Thus, drilling fluid flows into the hollow main body of the swivel via the inlet opening, then into the hollow segment of the drive shaft via the fluid openings in the drive shaft, and from there into the hollow interior of the pipe segments comprising the pipe drill string.
When the drilling rig is placed in a slanted position so that it can be used to drill an angled bore into the ground, a guide plate is removably secured to the lower end of the mast. The guide plate extends around the pipe drill string to help support the pipe drill string and hold it at the proper angle relative to the ground when drilling an angled bore.
When the drilling rig is placed in its vertical position so that it can be used to drill a vertical bore into the ground, a specially designed guide shoe is placed around the pipe drill string. Two halves of the guide shoe swing opens to facilitate attaching and removing it from the pipe drill string. The guide shoe has a downwardly extending lip that inserts within the shoe opening provided in the base plate, thus allowing the base plate to help keep the pipe drill string in approximately vertically alignment during drilling. The shoe opening is provided in a removable plate attached via bolts to the base plate. The removable plate can be removed to reveal a bit breaker opening, as will be discussed hereafter.
Pipe segments of the pipe drill string must be broken apart from each other to either add pipe to the pipe drill string or to remove pipe from the pipe drill string. In order to break the pipe segments apart, the guide shoe is first removed from the pipe drill string. Next, a backup wrench is inserted around the drill pipe so that the u-shaped head end of the backup wrench engages a flat portion on the end of the drill pipe. A downwardly extending lip provided on the specially designed backup wrench is next inserted into the shoe opening in the base plate. Then a traditional pipe-breaking wrench is employed to grasp a portion of the adjacent pipe. In order for the operator to handle a heavy traditional pipe-breaking wrench, a pulley is provided on the front side of the mast and a cable runs through the pulley. One end of the cable removably attaches to the winch that is attached to the frame and an opposite end of the cable removably attaches to the traditional pipe breaking wrench to assist the operator in lifting, positioning and holding the heavy pipe breaking wrench. One winch can be used for both holding the traditional pipe breaking wrench and for pivoting the swivel upward if the cables are removably attachable to either the winch or to both the traditional pipe breaking wrench and the swivel. Alternately, two separate winches may be employed.
A cable that attaches to a second hydraulic cylinder can be attached to the traditional pipe-breaking wrench in order to provide the necessary torque to break the pipes apart so that they can be unthreaded from each other.
When it is necessary to remove the drilling bit from the pipe drill string, the removable plate is removed from the base plate to reveal the bit breaker opening provided in the base plate. The bit breaker opening is employed for holding a bit breaker. The bit breaker is used to hold the bit so that it does not rotate relative to the base plate. This is necessary when the bit is disengaged from the pipe drill string by employing a method similar to the one described above for separating pipe segments.